Xanthoma


Xanthoma
Yellowish firm nodules in the skin frequently indicating underlying disease, such as diabetes, disorder of fats (lipid disorder or hyperlipidemia), or other conditions. A xanthoma is a kind of harmless growth of tissue. Under the microscope, a xanthoma can be seen to be composed of lipid-laden foam cells. These cells, termed histiocytes, contain lipid material in their cytoplasm (the nonnuclear zone of the cell). The word “xanthoma” is made up of “xanth-“ from the Greek roots “xanthos” (yellow) and “oma” (swelling) = a yellow swelling. A xanthoma is a circumscribed yellow swelling, a yellowish nodule.
* * *
A yellow nodule or plaque, especially of the skin, composed of lipid-laden histiocytes. [xantho- + G. -oma, tumor]
- x. diabeticorum eruptive x. associated with severe diabetes.
- x. disseminatum a rare benign normolipemic disorder of adults with coalescent cutaneous xanthomas composed of non-X histiocytes on flexural surfaces, often with mild diabetes insipidus.
- eruptive x. the sudden appearance of groups of 1–4-mm waxy yellow or yellowish-brown papules with an erythematous halo, especially over extensors of the elbows and knees, and on the back and buttocks of patients with severe hyperlipemia, often familial or, more rarely, in severe diabetes.
- x. multiplex SYN: xanthomatosis.
- x. palpebrarum SYN: xanthelasma palpebrarum.
- x. planum a form marked by the occurrence of yellow, flat bands or minimally palpable rectangular plates in the corium, either normolipemic or associated with type IIa or III hyperlipoproteinemia.
- tendinous x. x. involving tendons, ligaments, and fascia, forming deep, smooth, sometimes painful nodules beneath normal-appearing freely movable skin of the extremities; associated with abnormal lipid metabolism, commonly familial increased β lipoproteins, or obstructive liver disease.
- x. tuberosum xanthomatosis associated with familial type II, and occasionally type III, hyperlipoproteinemia. SYN: x. tuberosum simplex.
- x. tuberosum simplex SYN: x. tuberosum.
- verrucous x. histocytosis Y; a papilloma of the oral mucosa and skin in which squamous cell epithelium covers connective tissue papillae filled with large foamy histiocytes. SYN: histiocytosis Y.

* * *

xan·tho·ma zan-'thō-mə n, pl -mas also -ma·ta -mət-ə a fatty irregular yellow patch or nodule containing lipid-filled foam cells that occurs on the skin (as of the eyelids, neck, or back) or in internal tissue and is associated esp. with disturbances of lipid metabolism

* * *

n. (pl. xanthomata)
a yellowish skin lesion associated with any of various disorders of lipid metabolism. There are several types of xanthomata. Tuberous xanthomata are found on the knees and elbows; tendon xanthomata involve the extensor tendons of the hands and feet and the Achilles tendon. Crops of small yellow papules at any site are known as eruptive xanthomata, while larger flat lesions are called plane xanthomata.

* * *

xan·tho·ma (zan-thoґmə) [xanth- + -oma] a benign tumor composed of lipid-laden foam cells (macrophages containing lipid material). The most common types are in the skin, but xanthomas also appear elsewhere in the body. Called also lipoid granuloma. See also xanthomatosis. xanthomatous adj

Medical dictionary. 2011.